Process for breaking petroleum emulsions



' emulsion.

atented May s .1945" 2,375,539 raoonss Fort BRG PETROLEUM EMULsroNs I Melvin De Groote, University City, Mo assignor 1 to Petrolite Corporation, Ltd., Wilmington, Del, a corporation of Delaware N Drawing.

Application January 6, 1944,

9 Claims.

This invention relates primarily to the resolu-' tion of petroleum emulsions.-

One object of my invention. is to provide a novel process for resolving petroleum emulsions of the water-in-oil type, that are commonly-referred to as cut oil, roily oil," emulsified oil, etc, and which comprise. fine droplets of naturally-occurring waters or brines dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the Another object of my invention is to provide in the conventional manner. Such products, and

particularly the lower monoalkyl esters, maybe isomerized and polymerized substantially as de scribed in Industrial 8; Enginee1ing Chemistry,

32, 802-808 (1940) and 33, 86-89 (1941).-

In order to produce the sulfurized product, it

i is only necessary to resort to the conventional heat such products with elemental sulfur to pro' an economical and-rapid process for separating emulsions which have been prepared under controlled conditions from mineral 'oil, such as crude oil and relatively soft waters or biihes. Controlled emulsion and subsequentdem'ulsification under the conditions just mentioned, is of significant value in removing impurities, particularly inorganic salts, from pipe line oil.

' Demulsification, as contemplated in the present application, includes the preventive step of commingling the demulsifler with theaqueous component which would or might subsequently be- 'come either phase of the emulsion in absence of suchprecautionary measure.

The demulsifier ;or demulsifying agent employed in my herein disclosed process for resolving petroleum emulsions; consists of an oxyalkylation derivative of a lower alkyl ester of a polymerized higher fatty acid having a polyethylenic linkage, and more especially, those having consubsequent combinationwith the reactive olefin.-

oxide.

.iugated double bonds or the oxyalkylation'prodnot of a mixture of such esters. Similarly, the oxyalkylation derivatives of such sulfurized lower alkyl esters are included. The polymerization of such esters prior to sulfurization includes isomerization. Sulfurization-prob-' ably includes, atleast in part, the formation of other linkages involvingthe sulfur atom, and thus is a reaction or group of reactions comparable in nature to polymerization and isomerization, as far as enhanced molecular weight is concerned.

The sulfurized products are most conveniently prepared afterv the isomerization and polymerize tion step, although, as pointed out, one may sub-' ject the products to oxyethylation without suliurization; See U.- S. Patent No. 2,325,040, dated July 27, 1943, to Cook and Bradley. Much that issaid hereinafter in the discussion of these reactants is substantially as it appears in said patent.

One may prepare monoallsyl esters of unsaturated fatty acids having Dolyethylenic linkages,

'duce the corresponding s'ulfurized esters.

being subjected to sulfurization.

It is again emphasized, however, such p o u s may be subjected to oxyalkylation, without previously ticularly those containing from about 1 to 15% of sulfur, are especially suitable as reactants for contain'more than 15% of sulfur, provided that such products are still sub rubbery, or, in any event,are susceptible to reaction with a reactive oxyalkylating agent, such as ethylene oxide.

Thus, the reactants used prior to oxyalkylation,

whether rubbery or not, may be much more highly polymerized than those described in the aforementioned Cook'and Bradley patent.

In said Cook and Bradley patent the significant fe'ature required solubility in lubricating oil to the minimum extent of one-half of 1%.

furization, or both, might result in a product which would be insoluble in lubricating oil, and

so be of little or no value for the purpose set forth in said above mentioned Cook and Bradley patent. No such limitation exists in the present instance, and polymerization, or s'ulfurization, or both, may becarried to any suitabledegree, so long as'the product, prior to oxyethylation, or after oxyethylation, is sub-rubbery in nature;

that is, susceptible to convenient use in the manner hereinafter indicated. A; subsequently pointed out, in some instances'solubility of the composition equivalent to one part in 50,000 parts of emulsion may be perfectly serviceable. For

Obvi ously, excessive polymerization or excessive s1il' oxide or the like are those in which ester re- In arrangement or interchange takes place. other instances, aldehydric or ketonic carbonyl radicals may be effected; In a general way, oxyalkylation, and particularly oxyethylation, takes place at moderate temperatures, for instance, 150-200 0., under moderate pressures, for instance, not over 450 lbs. gauge pressure. Such reactions may be accelerated by means of a catalyst, suchas a small amount of alkali, as, for

instance, one-fourth percent of sodium methylate. Such reactions areconductedwith constant stirring, .so as to promote contact with the ethylene oxide or other oxyalkylating agent. Generally speaking, the reaction or series of re-. actions are conducted in a step-wise manner,

1. e., if one intended to introduce 4-20 moles of ethylene oxide per mole of monohydric alcohol ester, one might introduced 2 moles of ethylene oxide at a time until approximately onedialf the ethylene oxide had been introduced, and theremanner.

pounds is well known. For instance, acids, alco- SunrunrzxrronxPaocnnoaa Sulfurization procedure involves the addition of 1 to 15% or more of elemental sulfur, or its equivalent, to the polymerized esters. The temperature employed in 'sulfurization is approximately 150-475 C. The time of sulfurization may vary from 1 hour to 5 hours. 1

OXYALKYLATYION PROCEDURE Oxyalkylation. is conducted inthe conventional Oxyethylation of high molal comhols, amides, mercaptans, and thelike, arereadily susceptible to oxyethylation. The reaction involves a labile hydrogen atom. For example, a hydrogen atom attachedto a nitrogen atom, an oxygen atom, or a sulfur atom. Oxyalkylation may involve other reactions. For instance, it is known that total esters will react readily with after, the proportion may be increased until the total amount is introduced; The completeness of reaction is generally indicated by the disappearance of pressure, due to the absence of unreacted ethylene oxide, or the like.- Since such procedure, i. e., the oxyalkylation of fatty acid esters is Well known, elaborate description will be avoided, for the simple reason that the oxyalkylation of herein contemplated compounds takes place by the same procedure, except that the conditions for oxyalkylation are somewhat more vigorous, i. e., it is more diflicult to initiate and continue the reactions. the conditions of the reaction will be found sub.- sequently in regard to individual examples. Caution is required when glycide, or methyl glyclde, is employed,

PREPARATION or Unsaruxa'rnn Esraxs The methyl esters of soyabean fatty acids, or dehydrated castor oil fatty acid, linseed oil fatty acid, tune oil fatty acid, or other suitable acids, are prepared in the manner described in Industrial 8; Engineering Chemistry; 32, 802-808 (1940) Ethyl esters are prepared in a similar manner. The propyl, butyl, amyl and hexyl esters may also be utilized. The heptyl or octyl esters may also be employed.

DmearzA'rron or Low MOLAL Es'rras I The low molal esters of thekind previously described are isomerized and polymerized by heat treatment of 250 to 300 C. It is believed that the major portion of the product obtained'is a, dimer. The procedure followed essentially that described in preparing the dimerizedmetbyl esters and ethyl esters in the aforementioned technical reference. It was pointed .out in said reference that 5 to 25 hours is usually sumclent for polymerization, although-in some instances, a period of time as long as 50 hours may be employed.. Such polymerization or isomerization More details as to the ethylene oxide, and this is also true of certain carboxyl compounds not containing a labile hydrogen atom. Under more drastic'conditions a carbon-linked hydrogen atom may enter into reaction. The reaction can. generally'be hastoned by the addition of a small amount of an alkaline catalyst, such as caustic soda, sodium acetate, sodium carbonate, sodium bicarbonate, or sodium. methylate, Such reactions generally take place readily and do not require excessive pressure. The steps employed in the present instance are substantially the same as those de scribed in U. S. Patent No. 2,208,581, dated July 23, 1940, to Hoefielmann. The time of reaction varies with the amount of alkylene oxideabsorbed, The most suitable oxyalkylating agents are ethylene oxide, propylene, oxide, butylene oxide, glycidol, etc. However, there are other well known oxyalkylatingagents. For instance, U. S. Patent No. 2,208,581, dated July 23, 1940, to Hoeifelmann, enumerates the following: Glycerine epichlorhydrin, glycide alcohol, ethylene oxide, propylene oxide, butene-2-oxide, butene l-oxide, isobutylene oxide, butadiene oxide, butadiene dioxidechloroprene oxide, isoprene oxide; decene oxide, styrene oxide, cyclohexylene oxide, cyclopentene oxide, etc.

OXYALKYLATED Non-Sutmrzhn DERIVATIVE Example 1 The methyl esters of dehydrated castor oil fatty acids are isomerized and polymerized by heat treatment at 250-300 C. 'I'he'major-pormay be continued further by employing a longer period of time, forinstance, up to hours, or

by adding a mere trace of a suitable catalyst of .autoclave with46 lbs. of ethylene oxide.

tion of the product obtained consists of the methyl ester of dimerized conjugated linoleic ,(octadecadienoic) acid. lbs. of a polymerized material is mixed with 1 pound of sodium stearate, and then subjected to reaction in a suitable The oily compound having somewhat marked hydro-' phile properties, i. e., a tendency towards selfemulsification.

OXYALKYLATED NON-SULFURIZED DERIVATIVE Example 2 obtained is a self-emulsifying oil and represents an approximate molar ratio of 1 to 4.

OxYALKYLArao NCN-SULFURIZED DERIVATIVE Example 3' 135 lbs. of material obtained in the manner described in Example 2, preceding, is treated with 46 lbs. of ethylene oxide at a temperature of 170 C..for 8 hours. During this reaction period the pressure reached a maximum of 420 lbs. and dropped to zero. mate ratio of 1 to 8. The product so obtained shows solubility in water, with some persistent cloudiness, although markedly more soluble than the preceding example.

OXYALKYLATED Non-Surumzao DERIVATIVE Example 4 A batch of material, as described in the preceding example, was prepared and treated with an additional 136 lbs. of ethylene oxide. Substantially the same temperature, time and pressure conditions were employed as in the preceding example. This product represented an approximate molar ratio of 1 to 16. It was readily soluble in water to give a clear solution, without any disturbance or turbidity. The product is distinctly more water-soluble than the preceding example.

OxYALKYLATao NON-SULFURIZED DERIVATIVE Example 5 The same procedure is followed as in Examples 1 to 4, except that 145 lbs. of the corresponding ethyl esters are employed.

OxYALxYLATno NON-SULFURIZED DERIVATIVE Example 6 The same procedure is followed as in Examples 1 to 5, inclusive, except that the methyl or ethyl esters derived from soy'abean oil fatty acids are substituted in equal molar amount for those derived from dehydrated castor oil fatty esters.

OXYALKYLATED NoN-SULFURIzan DERIVATIVE Example 7 The same procedure is followed as in Examples 1 to 5, inclusive, except that the methyl or ethyl esters derived from linseed oil fatty acids are substituted in equal molar amount for those derived from dehydrated castor oil fatty esters.

OXYALKYLATED NON-SULFURIZED DERIVATIVE Example 8 This represents an approxi- .OXYALKYLATED NON-SULFURIZED DERIVATIVE Example 9 The same procedure is followed as in Examples 1 to 8, inclusive, except that a molecular equivalent of propylene oxide, butylene oxide, glycide or methylglycide, is substituted for ethylene oxide. Methyl glycide andglycide may react with almost explosive violence. These two reactants should be added in extremely small step-wise proportions and a somewhat lower temperature employed. Propylene oxide and butylene oxide react less readily than ethylene oxide, and may require a somewhat higher temperature, for instance, 25 to C. higher, and somewhat higher gauge pressure, for instance, a maximum of 400-450 lbs., and a somewhat longer time of reaction, for instance, a maximum of 25 to 40 hours.

fatty acids are isomerized and polymerized by heat treatment at 250-300 C. The major portion of the product obtained consists of the methyl ester of dimerized conjugated linoleic (octadecadienoic) acid. This product is heated with 10% of sulfur by weight, for 1 /23 hours at a temperature of 155-1650. A viscous brown liquid is obtained, which is then subjected to. treatment'with ethylene oxide. 150 lbs. of such viscous brown liquid is mixed with 1 lb. of sodium stearate and then subjected to reaction in a suitable autoclave with 46 lbs.-'of ethylene oxide. The temperature employed is aproximately 170 C., and the time approximately 15 hours. During this period the gauge pressure drop was from a maximum of 320 lbs. to 0 lbs; per square inch. The mass was agitated continuously during reaction period. The product so obtained is a dark amber, oily compound having somewhat marked hydroph ile properties, i. e., a tendency toward self-emulsiflcation.

QXYALKYLATED SULFURIZED DERIV TIVE Example 2 The same procedure-is followed as in the pre ceding example, except that after the initial drop to zero, a second batch, to wit, 46 lbs. more of ethylene oxide, were added, and reaction conducted for 10 hours, until there was a drop from 300 lbs. gauge pressure to zero. The product so obtained is a self-emulsifying oil and represents an approximate molar ratio of 1 to 4.

OXYALKYLATED SULFURIZED DERIVAT VE Example 3 lbs. of material obtained in the manner described in Example 2, preceding, is treated with 46 lbs. of ethylene oxide at a temperature of C. for 8 hours., During this reaction period the pressure reached a maximum of 400 lbs. and

dropped to zero. This represents anapproximate ratio of 1 to 8. The product so obtained shows solubility in water, with some persistent cloudiness, although markedly more the preceding example.

OXYALKYLATED SULFURIZED DERIVATIVE Example 4 soluble than stantially the same temperature, time and pres-.

The same procedure is followed as in Example 4, except that 155 lbs. of the corresponding ethyl esters are employed.

OXYALKYLATED SULFURIZED DERIVATIVE Example 6 The same procedure is followed as in Examples 1 to 5, inclusive, except that the methyl or ethyl esters derived from soyabean oil fatty acids are substituted in equal molar amount for those derived from dehydrated castor oil fatty esters.

OXYALKYLATED SULFURIZED DERIVATIVE Example 7 The same procedure is followed as in Examples 1 to 5, inclusive, except that the methyl or ethyl esters derived from linseed oil fatty acids, are substituted in equal molar amount for those de rived from dehydrated castor oil fatty esters.

QXYALKYLATED SULFURIZED DERIVATIVE Example 8 The same procedure is followed as in Examples 1 to 5, inclusive, except that the methyl or ethyl esters derived from tung oil fatty acids are substituted in equal molar amount for those derived from dehydrated castor oil fatty esters.

OXYALKYLATED SULFURIZED DERIVATIVE Example 9 The same procedure is followed as in Examples 1 to 8, inclusive, except that a molecular equivalent of propylene oxide, butylene oxide, glycide or methyl glyci de, is substituted for ethylene oxide. Methyl glycide and glycide may react with almost explosive violence. These two reactants should be added in extremely small step-wise proportions and a somewhat lower temperature I employed. Propylene oxide and butylene oxide react less readily than ethylene oxide, and may require a somewhat higher temperature, for instance, 25 to 50 C. higher, and somewhat higher gauge pressure, for instance, a maximum of 400- 460 lbs. and a somewhat longer time of reaction, for instance, a maximum of 25 to 40 hours.

OXYALKYLATED SULFURIZED DERivArIvE Example 10 The same procedure is followed as in Examples 1 to 9, preceding, except that of sulfur by weight, is employed instead of 10% by weight, and the period of sulfurization varied from approximately 2 hours to 4 /z hours.

'All the preceding examples are obtained from the non-fractionated polymerized esters. It has been previously pointed out that such non-fractionated products may contain a substantial amount of the monomeric esters, for instance, about to 35%. There is no objection to such monomer being present in the reaction. If de-- sired, however, the monomeric material can be removed by fractional distillation in the manner set forth in the technical references previously mentioned. Such reactant substantially free from the monomers can be substituted in all the various examples preceding.

,Conventional demulsifying agents employed in the treatment of oil field emulsions are used as such, or after dilution with any suitable solvent, such as water; petroleum hydrocarbons, such as gasoline, kerosene, stove oil, a coal tar product, such as benzene, toluene, xylene, tar acid oil, cresol, anthracene oil, etc. Alcohols, particularly aliphatic alcohols, such as methyl alcohol, ethyl alcohol, denatured alcohol, propyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol, etc., may be employed as diluents.

Miscellaneous solvents, such as pine oil, carbontetrachloride, sulfur dioxide extract obtained in the refining'of petroleum, etc. may be employed as diluents. Similarly, the material or materials herein described, when employed as demulsifiers for water-in-oil emulsions, may be mixed with one or more of the solvents customarily used in connection with conventional demulsifying agents. Moreover, said material or materials may be used alone, or in admixture with other suitablewell known classes of demulsifying agents.

It is well known that conventional demulsify ing agents may be used in a water-soluble form, or in an oil-soluble form, or in a form exhibiting both oil and water solubility. Sometimes they may be used in a form which exhibits relatively limited on solubility. However, since such reagents are sometimes used in a ratio of 1 to 10,000 or 1 to 20,000, or even 1 to 30,000, or even 1 to 40,000, or 1 to 50,000 in desalting practice, such an apparent insolubility in oil and water is not significant, because said reagents undoubted- .ly have solubility within the concentration employed. This same fact is true in regard to the material or materials herein described.

I desire to point out that the superiority of the reagent or demulsifying agent contemplated in my herein described process for breaking petroleum emulsions, is based upon its ability to treat certain emulsions more advantageously and at a somewhat lower cost than is possible with other available demulsifiers, or conventional mixtures thereof. It is believed that the particular demulsifying agent or treating agent herein described will find comparatively limited application, as far as the majority of oil field emulsions are concerned; but I have found that such a demulsifying agent has commercial value, as it will economically break or resolve oil field emulsions in a number of cases which cannot be treated as easily or at so low a cost with the demulsifying agents heretofore available.

In practising my improved process for resolving petroleum emulsion of the water-in-oil type, a treating agent or demulsifying agent of the kind above described, is brought into contact with or caused to'act upon the emulsion to be treated, in any of the various ways, or by any of the various apparatus now generally used. to resolve or break petroleum emulsions with a chemical reagent, the above procedure being used either alone, or in combination with other demulsifying procedure, such as the electrical dehydration process. I

The demulsifier herein contemplated may be employed in connection with what is commonly known as down-the-hole procedure, i. e., bringing the demulsifier in contact with the fluids of the well at the bottomof the well, or at some point prior to their emergency. This particular type of application is decidedly feasible when the demulsifler is used in connection with acidification of calcareous oil-bearing strata, especially if suspended in or dissolved in the acid employed for acidification.

I have found that the most valuable products, by far, are obtained by use of the oxyalkylatin agent, for instance, ethylene oxide, within the ratio of 10 moles of ethylene oxide per mole of higher fatty acid originally employed as the raw material.

As to other suitable fatty acids which can be converted into low molal esters and employed, see those specifically mentioned in the previous two literature references, and also in the aforementioned Cook and Bradley patent. Particularly see oiticica oil. I

Reference is made to my divisional application Serial No. 549,785, filed August 16, 1944, wherein the materials employed as the demulsifier of my herein described process, are claimed as new compositions of matter.

Having thus described my invention, what I claim as new and desire, to secure by Letters Patent is:

1. A process for breaking petroleum emulsions of the water-in-oil type, characterized by sub jecting the emulsion to the action of a demulsifier comprisinga member of the class consisting of oxyalkylated monohydric lower alkyl esters of a polymerized polyethylenic higher fatty acid and oxyalkylated sulfurized monohydric lower alkyl esters of a polymerized polyethylenic higher fatty acid.

double bonds.

3. The process ofclaim 1 wherein the poly- 2. The process of claim 1, wherein the polyethylenic higher fatty esters have conjugated ethylenic higher fatty esters have conjugated double bonds, and the number of carbon atomsin the oxyalkyl group are at least 2 and not over 4.

-5. The process of claim 1, wherein the 'polyethylenic higher fatty esters have conjugated double bonds, the, number of carbon atoms in the oxyalkyl group are at least 2 and not over and-the number of carbon atoms in the alkyl ester are not over 2. I

6. The process of claim 1, wherein the polyethylenic higher fatty acid esters have conjugated double bonds, the oxyalkyl group is an oxyethyl group; and the number of carbon atoms in not over 2.

the alkyl ester are not over 2.

7. The process of claim 1, wherein the higher fatty acidester is a dehydrated castor oil fatty acid ester, the oxyalkyl group'is an oxyethyl group, and the number of carbon atoms the 1 alkyl ester are not over 2.

8. The process of claim 1, wherein the higher fatty acid ester is an oiticica oil fatty acid ester,

the oxyalkyl group is an oxyethyl group,' and the number of carbon atoms in the alkyl ester are not over 2.

'9. The process of claim 1, wherein the higher fatty acid ester is a tungoil fatty acid ester, the

oxyalkyl group is an oxyethyl group, and the number of carbon atoms in the alkyl ester are MELVIN DE GROOTE. 

